THE FACE 



359 



Ossification. The premaxillary develops from one centre of 

 ossification. 



VARIATIONS IN THE PREMAXILLARY BONES. 



The premaxillary may be measured as follows : 



The maximum length is the distance from the anterior edge of the 

 alveolar border to the posterior tip of the palatine process. 



The width is the maximum transverse diameter of the inferior 

 aspect, from the median border of the palatine process to the outer 

 edge of the body, at the anterior lower angle of the articular surface 

 for the maxillary. 



The length of the body is the distance from the anterior median 

 point of the alveolar border, the so-called alveolar point, to the lower 

 posterior angle of the articular surface for the maxillary. 



The height is the shortest distance from the posterior angle of the 

 body to the tip of the nasal process. 



Variations in form appear to be confined to slight differences in the 

 inclination and degree of curvature of the nasal process ; in the promi- 

 nence of the tubercle on the anterior superior border of the body ; 

 and in the amount of depression of the external surface. 



HUMAN MAXILLARY BONES. 



Each human maxillary bone includes also the premaxillary of that 

 side of the skull ; although the premaxillary arises from a separate 

 centre of ossification, it coalesces so quickly with the maxillary that its 

 independent origin can be hardly recognized. 



